摘要
针对YJ3-X超深大斜度井三开井段存在的裂缝发育、井漏风险高、斜井段位移长、携砂困难、摩阻扭矩大、完井下套管作业时间长等钻完井难题,室内通过乳化剂的优选对现有抗高温油基钻井液体系配方进行了优化,并根据临井出现的复杂情况模拟该井可能出现的风险,评价了优化后钻井液体系的抗岩屑污染和盐水污染性能。试验结果表明,优化后的抗高温油基钻井液具有良好的流变性,抗温达180℃,破乳电压高达1366 V,高温高压滤失量低至2 mL,抗岩屑污染达20%,抗CaCl2盐水污染达30%,静置120 h后沉降因子为0.52,可满足井下各类复杂环境的作业需求。现场应用效果表明,优化后的抗高温油基钻井液流变性稳定,具有较低的黏度和较强的触变性,井眼清洁良好,起下钻和下套管摩阻低,井壁稳定,较好地满足了YJ区块大斜度深井作业需求。
In response to the drilling and completion challenges in the third spudding section of the YJ3-X ultra-deep and highly deviated well,such as fracture development,high risk of lost circulation,long displacement in deviated well sections,difficulties in carrying sand,high friction torque,and prolonged downhole casing operations,the existing high-temperature resistant oil-based drilling fluid system in the laboratory are optimized.This optimization primarily involved enhancing the emulsifier.The simulations to assess potential well risks in a near-well complex scenario are conducted and the drilling fluid system’s performance regarding anti-cuttings pollution and saltwater pollution are evaluated.The experimental results indicate that the optimized high-temperature resistant oil-based drilling fluid has excellent rheological properties,temperature resistance up to 180℃,demulsification voltage up to 1366 V,high temperature and high pressure filtration loss as low as 2 mL,resistance to cuttings pollution up to 20%,resistance to CaCl2 brine pollution up to 30%,and settlement factor of 0.52 after standing for 120 h,which can meet the operation requirements of various complex downhole environments.Field applications further demonstrate that the optimized high-temperature resistant oil-based drilling fluid exhibits stable rheology,low viscosity,strong thixotropy,excellent borehole cleanliness,reduced friction during tripping and casing operations,and stable borehole wall.These attributes make it particularly well-suited to the operational needs of highly deviated deep wells in the YJ block.
作者
张恒
赵晓亮
孔庆胜
孙鹏
ZHANG Heng;ZHAO Xiaoliang;KONG Qingsheng;SUN Peng(COSL Xinjiang Branch,Korla 841000,Xinjiang,China;COSL Oilfield Chemistry Division,Sanhe 065201,Hebei,China)
出处
《能源化工》
CAS
2024年第1期57-61,共5页
Energy Chemical Industry
关键词
超深大斜度井
油基钻井液
井眼清洁
抗污染
降摩阻
ultra-deep and highly deviated well
oil-based drilling fluid
borehole cleaning
anti-pollution
reducing friction
